Alternate plate construction for an impeller

ABSTRACT

A method and system for washing clothing in a washing machine. A washing device has impeller blades with movable blade tips for adjusting the amount of surface area of the blades depending on the water level in a basket of a washing machine. The movable blade tips may be connected to blade bases via a hinge and a spring. For high-water conditions, the movable blade tips are automatically positioned in a raised position, and for low-water conditions, the blade tips are automatically positioned in a lowered position. Advantageously, the invention can allow a single washing machine to have the cleaning ability of a washing machine having a low-water condition impeller and the rinsing ability of a washing machine having high-water condition agitator.

BACKGROUND

1. Field of the Invention

The present invention relates to washing machine technology and, more particularly, to an alternate plate construction for a washing machine impeller.

2. Description of Related Art

Washing machines have traditionally used an agitator to circulate clothing during a wash cycle to improve the effectiveness with which the washer cleans the clothing. Referring to the drawings, FIG. 1 is a side sectional view of an exemplary agitator-type washing device 100 used in traditional washing machines. The device 100 has a center agitator 102 provided within a vertical axis wash basket 104 that is rotatably supported within a tub 106. The agitator 102 extends upwardly from the bottom wall of the basket 104 and typically has a height that is substantially equal to the height of the wash basket 104. As illustrated, the agitator 102 generally includes a barrel 110, a base 114, and a plurality of vanes 116. Agitators, such as that illustrated in FIG. 1, typically operate in a high-water condition. During washing, the drive shaft of the washing machine oscillates the agitator 102 back-and-forth, causing the water inside of the basket 104 of the washing machine 100 to move, thereby circulating the clothing for improved washing and rinsing. Agitators, however, typically require a high-water condition during washing, thereby using relatively large amounts of water to the wash clothing. Additionally, the blades of the agitator can undesirably stress clothing during the washing.

In an effort to improve upon such undesirable characteristics of agitators, washing machine manufacturers have begun to use various alternative washing devices, such as an impeller, to circulate clothing during the washing cycle. FIG. 2 is a side sectional view of a vertical axis washing machine 150 wherein a relatively flat or low height, disk-like impeller or pulsator 152 is provided along the bottom wall of a wash basket 154 that may be rotatably supported within a tub 156. As illustrated, the impeller 152 generally includes a plate 158 and a plurality of blades 160 coupled to the plate 158. During washing, the drive shaft of the washing machine 150 oscillates the impeller 152 back-and-forth, thereby circulating the clothing inside of the washing machine for improved washing and rinsing. Because the impeller 152 physically moves the clothing itself, rather than moving the clothes via water movement, the impeller 152 can operate under low-water conditions, as described in commonly owned U.S. Pat. No. 6,212,722, hereby incorporated by reference. Consequently, washing machines having an impeller 152 generally use less water during washing than do washing machines with an agitator 152. Further, these alternative washing devices are generally gentler on the clothing, provide improved cleaning capability, and allow a user to wash more clothing in a single load, compared to agitator-type washing machines.

Unfortunately, however, due to the low-water operating conditions, washing machines using alternative washing devices may not rinse clothing as well as agitator-type washing machines. Additionally, alternative washing devices are typically not as well suited to washing large items, such as a blanket, for instance, as are agitator-type washing machines. Therefore, an improved method and system for washing clothing in a washing machine having the benefits of both agitator-type washing machines and washing machines using alternative washing devices (e.g., an impeller) is desired.

SUMMARY

The present invention provides an alternate plate construction for an impeller washing device. According to an exemplary embodiment of the invention, a washing device for use in a washing machine is provided. The washing machine is comprised of a plate and a plurality of blades. Each of the blades comprises a blade base coupled to a first surface of the plate and a blade tip coupled to the blade base. Each of the blades is approximately perpendicular to the first surface of the plate and each of the blade tips is movable to allow for adjusting surface area of the plurality of blades.

These and other aspects and advantages of the present invention will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, it should be understood that the foregoing summary is merely exemplary and is not intended to limit the scope of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of the present invention is described herein with reference to the drawings, in which:

FIG. 1 is a side sectional view illustrating a conventional washing machine having an agitator;

FIG. 2 is a side sectional view illustrating a conventional washing machine having a bottom impeller;

FIG. 3 is a side sectional view of a washing machine having an impeller in accordance with the exemplary embodiment;

FIG. 4 is a partial perspective view of an impeller with flexible tips illustrated with the tips in a raised position in accordance with the exemplary embodiment;

FIG. 5 is a partial perspective view of an impeller with flexible tips illustrated with the tips in a lowered position in accordance with the exemplary embodiment; and

FIG. 6 is a side cutaway view of an impeller blade in accordance with the exemplary embodiment.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT

Referring to the drawings, FIG. 3 is a perspective view of a washing machine 200. As illustrated, the washing machine 200 generally includes a housing 202, a basket 204, a tub 206, a user interface 208, and a drive shaft 210 that can be coupled to a modified impeller 300 for circulating clothing during washing. Other and/or additional or fewer components than those shown in FIG. 3 are possible for use in the washing machine 200.

FIG. 4 is a partial perspective view of the modified impeller 300 that may be used in a washing machine in accordance with an exemplary embodiment of the present invention. As illustrated, the modified impeller 300 may include plate 302, a plurality of blades 304, each blade 304 comprising a blade base 306 coupled to a first surface 308 of the plate 302, and a blade tip 310 movably coupled to the blade base 306. With the blade tips 310 movably coupled to the blade bases 306, the blade tips 310 may be placed in a raised position, a lowered position, or a position between the raised and lowered positions. (In FIG. 4, the modified impeller 300 is shown with its blade tips 310 in a raised position). Other and/or additional or fewer features are possible for the modified impeller 300 than those discussed herein.

The modified impeller 300 may be any size that will allow it to fit within the basket of the washing machine. Preferably, the modified impeller 300 will be sized in such a way that the plate 302 will be approaching the size of the bottom of the basket 204. In the preferred embodiment, the modified impeller 300 may be fabricated from polypropylene, for instance. The modified impeller 300 could additionally or alternatively be fabricated from other plastics, metal, rubber, and/or other suitable materials.

The size of the blades 304 during both the raised and the lowered positions are preferably dependent upon the number of blades 304 on the impeller 300. Generally, the more blades 304 that the modified impeller 300 has, the smaller the blades 304 should be during both the raised and the lowered positions. In the exemplary embodiment shown in FIG. 4, the modified impeller 300 has six blades 304. In this embodiment, the height of the blades 304 at their highest point during the lowered position is approximately one inch, and during the raised position is approximately one-and-a-half inches. Other numbers of blades and blade sizes are also possible. In the raised position, the shape of the blades 304 in the exemplary embodiment is sloped upward from the center of the modified impeller 300 toward the outside of the modified impeller 300. In the lowered position, as in the raised position, the blades 300 are sloped upward from the center of the modified impeller 300 toward the outside of the modified impeller 300. However, near the outside of the modified impeller 300, the height of the blades 304 plateau in the area where the blade tips 310 are coupled to the blade bases 306. Other blade shapes and sizes are also possible other than those discussed herein.

The blade tips 310 may be coupled to the blade bases 306 in a manner that allows the blade tips 310 to be placed in the lowered position, with at least a portion of the blade tips 310 recessed within the blade bases 306, or in the raised position, with less of the blade tips 310 recessed within the blade bases 306. When the blade tips 310 are in the raised position, the surface area of the blades 304 are increased, and when the blade tips 310 are in the lowered position, the surface area of the blades 304 is decreased. This change in blade surface area allows the modified impeller 300 to operate in both a low-water condition (with the blade tips 310 in the lowered position) and a high-water condition (with the blade tips 310 in the raised position). Additionally, reducing the surface area of the blades 304 can torque limit a motor of the washing machine so that excessive torque is not applied to it.

FIG. 5 is a partial perspective view of the modified impeller 300 of FIG. 4 with blade tips 310 shown in a lowered position. When in the lowered position illustrated in FIG. 5, the modified impeller 300 is suited to operate in the low-water condition.

FIG. 6 is a partial side cutaway view of a blade 304 of the modified impeller 300 in accordance with the exemplary embodiment of the present invention. The blade tip 310 may be coupled to the blade base 306 via a hinge 500 and a spring 502. The hinge 500 may be located at the point where the blade base 306 and the end of the blade tip 310 that is closest to the middle of the plate 302 meet. The hinge 500 may be any type of hinge, including a simple interlocking hinge, such as is shown in FIG. 6. The spring 502 is captured between an inner surface 506 of the tip 310, adjacent a curved surface 312, and an inner surface 508 of the blade base 306. The blade tips 310 may be in a raised position when they are unloaded or are only lightly loaded (with clothing submerged in a high-water condition), and the blade tips 310 may be moved to a lowered position when they are sufficiently loaded (with clothing in a low-water condition, for instance).

In an alternative embodiment, rather than (or in addition to) using a spring 502, the blade tips 310 may be coupled to the blade bases 306 via the hinge 500 and the blade tips 310 may be fabricated from a material that is buoyant in water. For such an embodiment, when a low-water condition exists in the washing machine basket, the blade tips 310 may be in a lowered position, but when a high-water condition exists in the basket, the blade tips 310 may be moved to a raised position due to the buoyancy of the blade tips 310 in the water. Other methods of securing the blade tips 310 to the blade bases 306 and controlling the position of the blade tips 310 are also possible.

When using a washing machine with the modified impeller of the present invention, a user places clothing to be washed and detergent inside of the washing machine. Next, the user inputs washing instructions into the washing machine. The washing machine can receive the washing instructions via the user interface, for instance. The user input may include, for instance, that the wash cycle should be a low-water condition wash, and the rinse cycle should be a high-water condition rinse. High-water wash and a low-water rinse user inputs are also possible. Alternatively, if the user does not specify the water condition during the wash or rinse cycles, the washing machine could, by default, use a low-water condition for the wash cycle and a high-water condition for the rinse cycle.

Finally, the washing machine washes the clothing. The movable blade tips 310 are positioned in a raised position for high-water condition cycles and in a lowered position during low-water condition cycles. For spring-loaded hinged blade tips 310, such as illustrated in FIG. 6, the water level may automatically position the blade tips 310 in a raised or lowered position. For a low-water condition, the blade tips 310 may automatically be positioned in the lowered position because the weight of the clothing in the washing machine basket may push the blades 310 down to the lowered position. However, for a high-water condition, the blade tips 310 may automatically be positioned in the raised position because the high-water condition causes the clothing to float somewhat in the water, thereby decreasing the force of the clothing on the blade tips 310.

Similar to the spring-loaded hinged blade tips 310 above, in an alternative embodiment, for blade tips 310 made from material that is buoyant in water, the water level may automatically position the blade tips 310 in a raised or lowered position. This may be so because in the low-water condition there will not be enough water in the basket 204 for the blade tips 310 to float to the raised position. Therefore, the blade tips 310 will remain in the lowered position. However, for a high-water condition, the greater amount of water in the basket will be adequate to allow the blade tips 310 to float.

An exemplary embodiment of the present invention has been described above. Those skilled in the art will understand, however, that changes and modifications may be made to this embodiment without departing from the true scope and spirit of the present invention, which is defined by the claims. 

1. A washing device for use in a washing machine comprising: a plate having a first surface; and a plurality of blades, each blade comprising: a blade base coupled to a first surface of the plate; and a blade tip coupled to the blade base; wherein each of the plurality of blades is approximately perpendicular to the first surface of the plate and has a movable tip to allow for adjusting surface area of the blade.
 2. The washing device of claim 1 wherein the washing machine is a vertical-axis washing machine.
 3. The washing device of claim 1 wherein the device is fabricated from at least one of plastic, metal, and rubber.
 4. The washing device of claim 3 wherein the plastic is polypropylene.
 5. The washing device of claim 1 wherein the blade tip is coupled to the blade base via at least one of a hinge and a spring.
 6. The washing device of claim 5 wherein the hinge is spring-loaded to control the orientation of the blade tip relative to the blade base.
 7. The washing device of claim 1 wherein the blade tip is fabricated from a material that is buoyant in water.
 8. A washing machine comprising: a tub; a motor; and a washing device comprising: a plate having a first surface; and a plurality of blades, each blade comprising: a blade base coupled to a first surface of the plate; and a blade tip coupled to the blade base; wherein each of the plurality of blades is approximately perpendicular to the first surface of the plate and has a movable tip to allow for adjusting surface area of the blade.
 9. The washing machine of claim 8 wherein the washing machine is a vertical-axis washing machine.
 10. The washing machine of claim 8 wherein the plate and the plurality of blades are fabricated from at least one of plastic, metal, and rubber.
 11. The washing machine of claim 10 wherein the plastic is polypropylene.
 12. The washing machine of claim 8 wherein the blade tip is coupled to the blade base via at least one of a hinge and a spring.
 13. The washing machine of claim 12 wherein the hinge is spring-loaded to control the orientation of the blade tip relative to the blade base.
 14. The washing machine of claim 8 wherein the blade tip is fabricated from a material that is buoyant in water.
 15. A method for washing clothing in a washing machine having a washing device with a plurality of blades having movable tips, the method comprising: receiving clothing inside the washing machine; receiving a wash input from a user; and washing the clothing; wherein washing step further comprises positioning the movable blade tips in a raised position for high-water conditions and in a lowered position for low-water conditions.
 16. The method of claim 15 wherein the low-water and high-water conditions occur in response to the wash input.
 17. The method of claim 15 wherein the low-water conditions occur during a wash cycle and the high-water conditions occur during a rinse cycle. 